The invention relates to an electric rotating machine comprising a rotor, a stator surrounding the rotor, and an air gap between the rotor and the stator.
The invention also relates to a compressor drive, ship or submarine having at least one encased (encapsulated) electric rotating machine of the aforesaid type.
The invention further relates to a method for producing an encapsulated stator.
An encapsulated electric rotating machine of the aforesaid type finds application for example in a, preferably integrated, compressor drive, wherein the drive itself is immersed in a gas atmosphere. The gaseous medium that is to be conveyed, natural gas for example, may contain aggressive substances which can attack the stator, in particular the stator windings, or the rotor, in particular the rotor windings.
An encapsulated electric rotating machine of the aforesaid type also finds application in ship propulsion drives, wherein seawater is circulated around the stator, for example in order to cool the latter. The stator and/or rotor may also be attacked by the salt contained in the seawater.
An electric machine comprising a stator encapsulated in a pressure-resistant enclosure for an integrated compressor drive is known from the published unexamined German patent application WO 2004/107532 A1, wherein the winding overhangs of the stator are embedded in a solid bracing structure on which the encapsulation is supported.
An encapsulated electric machine is known from the published unexamined German patent application WO 2008/046817 A1, wherein, in order to ensure efficient cooling, the stator has a liquid cooling apparatus comprising a corresponding stator cooling circuit, wherein the encapsulation forms a part of the outer wall of the cooling circuit.
A submersible electric propulsion motor which includes a sealed cylindrical stator housing is known from the patent specification U.S. Pat. No. 4,831,297 A.
An electric machine having a fully encapsulated stator is known from the patent specification U.S. Pat. No. 4,831,297 A, wherein a composite layer is interposed between the stator and an air gap.
A method for producing a stator is known from the published unexamined German patent application DE 10 2008 043386 A1, wherein a laminated yoke core and a star-type laminated stator core are connected to one another in a force-fit manner, for example by thermal shrinking, or in a form-fit manner, by means of recesses in the laminated yoke core for the ends of the stator teeth.